Device for finishing metallic surfaces



` y J. A. MACKINNON.

Device for Finishing Metallic Surfaces.

No. 242,950. Patented June 14,1881.y i

N Il y n t been previously turned or bored out in the ordinary manner, is arranged between the clamping-jaws, as shown, and the movable jaw C is pressed tightly against the box by means of the screws D. A compressing-tool ot' the form shown in Fig. 3, and havin gits enlargement l made about one-sixteenth of an inch larger than the bore of the box, is then forced through the bore by means of any suitable press. The metal of the box is thereby compressed to the size ofthe enlargement lof the tool. It' the desired caliberis larger than this tirst tool, a second and third tool are forced through the bore, all of similar construction and increasiiig slightly in size, the last tool forced through being ot' the exact caliber to which it is desired to finish the article. In this manner all the axle-boxes or other articles which are finished by the same tool are made of exactly the same caliber, Without requiring anyparticular skill on the part of the operator. Solid cylindricalparts are finished in the same manner by forcing a hollow compressing-tool, M, over the article. The tool M is provided With a cylindrical bore, which is slightly beveled at the end which first comes in contact with the article operated upon. The tool is arranged in a suitable head or carrier, which is of sufficient strength to prevent the expansion of the tool, and is forced over the article by a suitable press. If the article is ofa shape which does not permit the compressing-tool M to pass over it from end to end-as, for instance, the carriage-spindle shown in Fig. 4- the article is reversed when the tool has reached the limit of its movement and the tool is forced back by the press. The compressingtools are constructed of steel and hardened, so as to be perfectly rigid and unyielding.

By inishin g articles by compression, as above described, the pores of the metal are closed and the bearin g-surfaces are made harder and smoother than by the ordinary mode of finishing, which merely renders the metal smooth without increasing its density, and the articles produced by my process are consequentlybetter adapted to resist Wear, and operate with less friction.

My improved method of finishing is especially valuable in the construction of articles which are manufactured in. large quantities, and which are required to be of exactly the same caliber, so that each one may take the place of another in a machin e-a s, forinstance,

cotton-spindles, carriage-spindles, ctc.

By forcing the compressing-tool over the turned or bored surface of the article under treatment toward the end at which the article is supported the metal is prevented from tlowing in the longitudinal direction ofthe article', but is displaced in a lateral direction, thereby rendering the metal -more compact without causing the article to become lengthened or extended.

I claim as my invent-ion- 1. rEhe method ofsimultaneonsly gaging and finishing metallic articles of straight cylindrical form, which consists in first turning or boring the article and then forcing one or more compressing-dies having an unbroken surface externally over the turned surface of a solid cylinder, or internally over the bored surface ofthe holloW cylinder toward the end at which the cylinder is supported, whereby the metal is condensed to a given caliber without elongation, and at the same time polished.

2. Aclamping apparatus composed of a fixed jaw, B, movable jaw C, actuating-screws D, and removable bearings h L, substantially as set forth.

JOHN A. MAGKINNON.

Witnesses:

JNO. J. BONNER, EDW. J. BRADY. 

